共查询到20条相似文献,搜索用时 15 毫秒
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Singhal S. Le Gall D. Chen C.-T. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1990,78(7):1233-1249
Some digital source coding techniques for speech and video are reviewed. Predictive coding of speech, multipulse and code-excited coders and frequency-domain coders are discussed and compared for the coding of speech signals, and intraframe and still image coding and interframe coding are examined for the coding of image and video signals. The emphasis is on those algorithms that offer high compression while maintaining the perceptual quality of the source signals are discussed. Some algorithms that are general waveform coding algorithms and do not strictly depend on the input source are included 相似文献
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This paper presents a general framework for combined source-channel coding within the context of subband coding. The unequal importance of subbands in reconstruction of the source is exploited by an appropriate allocation of source and channel coding rates for the coding and transmission of subbands over a noisy channel. For each subband, the source coding rate as well as the level of protection (quantified by the channel coding rate) are jointly chosen to minimize the total end-to-end mean-squared distortion suffered by the source. This allocation of source and channel coding rates is posed as a constrained optimization problem, and solved using a generalized bit allocation algorithm. The optimal choice of source and channel coding rates depends on the state of the physical channel. These results are extended to transmission over fading channels using a finite state model, where every state corresponds to an additive white Gaussian noise (AWGN) channel. A coding strategy is also developed that minimizes the average distortion when the channel state is unavailable at the transmitter. Experimental results are provided that demonstrate application of these combined source-channel coding strategies on video sequences 相似文献
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In this paper, we develop an approach toward joint source-channel coding for motion-compensated DCT-based scalable video coding and transmission. A framework for the optimal selection of the source and channel coding rates over all scalable layers is presented such that the overall distortion is minimized. The algorithm utilizes universal rate distortion characteristics which are obtained experimentally and show the sensitivity of the source encoder and decoder to channel errors. The proposed algorithm allocates the available bit rate between scalable layers and, within each layer, between source and channel coding. We present the results of this rate allocation algorithm for video transmission over a wireless channel using the H.263 Version 2 signal-to-noise ratio (SNR) scalable codec for source coding and rate-compatible punctured convolutional (RCPC) codes for channel coding. We discuss the performance of the algorithm with respect to the channel conditions, coding methodologies, layer rates, and number of layers. 相似文献
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Nayak J. Tuncel E. Rose K. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(10):4626-4629
This correspondence presents a novel application of the theta function defined by Lovasz. The problem of coding for transmission of a source through a channel without error when the receiver has side information about the source is analyzed. Using properties of the Lovasz theta function, it is shown that separate source and channel coding is asymptotically suboptimal in general. By contrast, in the case of vanishingly small probability of error, separate source and channel coding is known to be asymptotically optimal. For the zero-error case, it is further shown that the joint coding gain can in fact be unbounded. Since separate coding simplifies code design and use, conditions on sources and channels for the optimality of separate coding are also derived 相似文献
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Arithmetic coding algorithm with embedded channel coding 总被引:2,自引:0,他引:2
A joint lossless source and channel coding approach that incorporates error detection and correction capabilities in arithmetic coding is exploited. The encoded binary data representation allows the source decoder to recover the source symbols, even with channel errors. The self-synchronisation property of arithmetic coding, the knowledge of the source statistics, and some added redundancy are used for error detection and correction 相似文献
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Elias提出的间隔编码和新近队列编码对统计特性未知的信源是良好的自适应信源编码.本文论证了间隔编码和新近队列编码的效率以概率队列编码的效率为上界,并将Elias的离散无记忆信源模型下的间隔编码和新近队列编码推广到了有限状态有记忆信源. 相似文献
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Jun Chen Berger T. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2008,54(4):1586-1603
In this paper, we introduce a distributed source coding scheme called successive Wyner-Ziv coding. We show that every point in the rate region of the quadratic Gaussian CEO problem can be achieved via successive Wyner-Ziv coding. The concept of successive refinement in single source coding is generalized to the distributed source coding scenario, which we refer to as distributed successive refinement. For the quadratic Gaussian CEO problem, we establish a necessary and sufficient condition for distributed successive refinement, where the successive Wyner-Ziv coding scheme plays an important role. 相似文献
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Steinberg Y. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(11):4995-5010
This work studies problems of source and joint source-channel coding under the requirement that the encoder can produce an exact copy of the compressed source constructed by the decoder. This requirement, termed here as the common reconstruction constraint (CR), is satisfied automatically in rate-distortion theory for single sources. However, in the common formulation of problems of lossy source coding with side information at the decoder (the Wyner-Ziv problem), distributed source coding, and joint source-channel coding for networks, the destination can exploit the information it receives in a manner that cannot be exactly reproduced at the sender side. Some applications, like the transmission of sensitive medical information, may require that both sides-the sender and the receiver-will share a common version of the compressed data, for the purpose of future discussions or consulting. The purpose of this work is to study the implications of CR constraints on the achievable rates in scenarios of lossy source coding and lossy transmission of sources. Three problems are examined: source coding with side information at the decoder, simultaneous transmission of data and state over state-dependent channels, and joint source-channel coding for the degraded broadcast channel. Single-letter characterizations of the optimal performance are developed for these problems, under corresponding CR constraints. Implications of this constraint on problems of joint source-channel coding in networks are discussed. 相似文献
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Hans Georg Musmann 《Signal Processing: Image Communication》1995,7(4-6):267-278
Known coding techniques for transmitting moving images at very low bit rates are explained by the source models on which these coding techniques are based. It is shown that with motion-compensated hybrid coding, object-based analysis-synthesis coding, knowledge-based coding and semantic coding, there is a consistent development of source models. In consequence these coding techniques can be combined in a layered coding system. From experimental results obtained for object-based analysis-synthesis, coding estimates for the coding efficiency of such a layered coding system are derived using head and shoulder video telephone test sequences. It is shown that an additional compression factor of about 3 can be expected with such a complex layered coding system, when compared to block-based hybrid coding. 相似文献
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一种分簇无线传感器网络中的分布式信源编码算法 总被引:1,自引:0,他引:1
针对密集型无线传感器网络中信息存在大量冗余的问题,该文提出了一种适用于分簇无线传感网络的分布式信源编码算法。该算法以边信息作为初始参考信源,利用信源间的相关性来决定各信源的编码顺序和参考信源,然后由各信源相对于参考信源进行相关编码,接收端则根据编码顺序和参考信源进行相关译码。该文同时针对模值编码的方式,给出了一种低复杂度的译码算法。理论分析和仿真结果表明,将该算法应用于分簇路由协议中可以有效地降低节点的发送比特数,从而降低网络的能耗以延长网络寿命。 相似文献
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无线中继与网络编码是提高通信系统数据可靠性和吞吐率的重要技术手段,重点研究了单中继非正交多址系统复数域网络编码的优化设计问题.首先,在限制源节点和中继节点的总发送功率并假设各个源节点发送功率相同的条件下,证明了当源节点与中继节点发送功率相等时基于复数域网络编码的单中继非正交多址系统误符号率(SEP)性能最佳.其次,以编码增益为目标函数,提出了一种复数域网络编码的优化设计方法.与已有的复数域网络编码系数设计方法相比,此方法能满足任意源节点个数条件下复数域网络编码系数的优化设计要求,同时可以有效地避免因为网络编码系数选择不当造成信号重叠的现象,提升和改进系统的SEP性能. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》1977,23(4):466-472
A coding scheme for the binary memoryless source is presented. The scheme is an extension of a scheme discovered by Lynch and Davisson and developed by Schalkwijk, and is based upon the Schalkwijk algorithm for the Lynch-Davisson (LD) code. The new coding scheme is shown to be asymptotically optimal as the block length approaches infinity, regardless of the source statistics. Although the LD scheme is minimax-universal, it is not optimal for low source entropies and finite block lengths. Run length coding is shown to be closer to optimal for low source entropies, and the new scheme is shown to be practically equivalent to run length coding in this range. 相似文献
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Operational rate-distortion performance for joint source andchannel coding of images 总被引:1,自引:0,他引:1
This paper describes a methodology for evaluating the operational rate-distortion behavior of combined source and channel coding schemes with particular application to images. In particular, we demonstrate use of the operational rate-distortion function to obtain the optimum tradeoff between source coding accuracy and channel error protection under the constraint of a fixed transmission bandwidth for the investigated transmission schemes. Furthermore, we develop information-theoretic bounds on performance for specific source and channel coding systems and demonstrate that our combined source-channel coding methodology applied to different schemes results in operational rate-distortion performance which closely approach these theoretical limits. We concentrate specifically on a wavelet-based subband source coding scheme and the use of binary rate-compatible punctured convolutional (RCPC) codes for transmission over the additive white Gaussian noise (AWGN) channel. Explicit results for real-world images demonstrate the efficacy of this approach. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》1980,26(6):679-692
For arbitrary alphabets and single-letter fidelity criteria, two theorems are given which allow any fixed-rate or variable-rate source coding theorem for block codes to be extended to sliding-block codes. Applications are given to universal coding and to the coding of a stationary nonergodic source. 相似文献
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Adaptive source coding is investigated which is performed by a blockwise classification of the source symbols and selection of a coder depending on the class. As justification for adaptive coding, an upper bound is used for the rate distortion function of a stationary source depending on blockwise classification. The main result of the paper states that classification is appropriate to exploit statistical dependencies other than correlation. Such statistical dependencies are described for the prediction error of a coding scheme for moving pictures at 64 kbit/s and are exploited for upper bounding the rate distortion function of the prediction error and improving the coding scheme 相似文献